Mysterious Tracks Discovered at the Bottom of Belize's Great Blue Hole

What’s really lurking down there at the bottom of Belize’s Great Blue Hole? This past December, a team of scientists embarked on a mission to map and explore the bottom of this world-famous marine sinkhole. They found some never-before-seen anomalies inside, including some mysterious tracks at the very bottom.

The exploration team included Jacques Cousteau’s grandson, Fabien Cousteau. Now that the scientists have returned, they’re sharing their discoveries in the form of images, video footage, 3D mapping, and an upcoming documentary. The groundbreaking mission employed two submarines and high-resolution sonar to unearth the sinkhole’s mysteries.

One of the team’s submarines on the edge of Lighthouse Reef.
*Credit: Aquatica Submarines/Thomas Bodhi Wade*

As for the unidentified tracks, submarine pilot Erika Bergman said they are “open to interpretation” in an interview with CNN Travel.

However, over 20 dives into the hole brought to light (literally) a plethora of interesting (and identifiable) discoveries. The explorers mapped and photographed stalactites at the bottom of the sinkhole. Bergman told CNN that this was a major discovery, since the stalactites were found in areas that had never been explored.

This time, however, the team’s high-resolution sonar equipment was able to use some of the latest technology to create a 3D sonar map of nearly the entire hole. “You can be 20 or 30 meters away from a stalactite or a hunk of the wall and see it in every perfect detail, better than eyesight could even provide,” Bergman said.

Strange discoveries

Besides the mysterious tracks, the sonar scans unearthed many other significant discoveries. Icicle-shape mineral formations can be seen among the stalactites near the bottom of the hole. In addition, there’s a “conch graveyard”. It is the final resting place of thousands of conch that have fallen into the abyss.

Close to the bottom, there is no oxygen. At about 300 feet down, there is a thick layer of hydrogen sulphide, a toxic gas. These conditions prevent any creatures from living deep within the hole.

Due to this toxicity, it’s clear that the mysterious tracks probably don’t belong to a ferocious sea monster. Nevertheless, the scientists did discover another sort of threat to our seas down at the bottom: plastic bottles. Richard Branson, one of the members of the exploration team, wrote about this discovery in his blog: “Sadly, we saw plastic bottles at the bottom of the hole, which is a real scourge of the ocean. We’ve all got to get rid of single-use plastic.”

An explanation for the tracks

So, if they don’t belong to sea monsters, how did those tracks get there? Bergman explained her own theory about the tracks in her blog. She believes they were created by thousands of unfortunate conch that slipped into the hole and were unable to escape. “We can see each conch with little tracks back up the hill trying to escape, then a slide mark where it slid back down after presumably being asphyxiated in the anoxic environment,” she wrote.